Fuel injection pump



Jan- 26 1960 w. o. BlsczHoFF` 2,922,371

FUEL INJECTION PUMP Filed July 5, 1957 65 69 65 23 '5 INVENTOR.

6a WALDEMAP @Blaat-orr- A TTOP/VE United States Patent O FUEL INJECTIONPUMP Waldemar 0. Bischoff, Holyoke, Mass., assig'uor to American BoschArma Corporation, a corporation of- New York Application July 5, 1957,Serial No. 670,178 s claims. (ci. 10s- 2) This invention relates todistributor type fuel injection pumps and has particular reference to anew and improved pump of the type set forth whichis relatively simple,compact and economical in construction, yet eilicient in operation.

Thel principal object of the invention is to provide a new and improvedfuell injection pump of the type set forth Yhaving simplied andeconomical Vconstruction means.

Other objects and advantages of the invention will be apparent from thefollowing description taken in 'connection with the accompanyingdrawings. It will be understood that changes may be made in the detailsof construction and arrangement of parts shown and described withoutdeparting from the spirit of the invention, as set -forth in theaccompanying claims, as the preferred form of the invention has beengiven by way of illustration only.

Referring to the drawings:

Fig. 1 is a longitudinal sectional view in a fuel injection apparatusembodying the invention;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1, looking in thedirection of the arrows; v

Fig. 3 is a fragmentary sectional view taken on line 3 3 of Fig. 1,looking in the direction of the arrows; and

Fig. 4 is a fragmentary sectional view taken von line 4 4 of Fig. 1,looking in the direction of the arrows.

Referring more lparticularly to the drawings 'wherein ysimilar referencecharacters designate corresponding parts throughout, the apparatus shownembodying the invention includes a housing in which is positionedhydraulic head 11, which could be vformed in the housing and lwhich hasa bore 11a in which is mounted the rotary Vmember or rotor 12 adapted tobe driven by the drive shaft 13 which is journaled in the housing. I

The rotor 12 has the pumpingl portion 14 and .the fuel distributingportion 15.

Thepumping portion has cylinder means consisting of a i radial bore 16in which is positioned piston means consisting of the opposed plungersi7, which are adapted to 'be urged outwardly on their suction stroke bythe spring 18, which is positionedv between the plungers and extendsinto bores in the adjacent surfaces of the plunger.

Surrounding the pumpingA portion 14 is the internal cam 18 havingopposed lobes for effecting simultaneous reciprocation of plungers 17and between the cam 18 and plungers 17 is provided the tappets 19y androllers 20.

The rotor 12 has a bore 21, the outer end of which is l adapted to beclosed by the plug 22 which has a reduced extension 23 extending intotheportion of bore 21 adjacent pumping portion 14.

The housinglu has the fuel inlet 23a adapted to be connected to a sourceof fuel, whichfuel passesV throug'hrinlet 23a toy annular sump 24surrounding hydraulic head 11 and is adapted to supply yfuel to bore 21by means of fill ports 25, which por-ts can be lof desired number;

Hydraulic head 11 is provided with a plurality of outlets 26, eachV ofwhich is4 adapted' to be' connected 'toV a respective engine cylinder orcombustion chamber for ICC supplying fuel thereto, and the outlets 26are adapted to receive `fuel through ports 27 from distributing grooveor slot V28 on the distributing portion of the rotor which, inturn,receive fuel through annular groove or slot 29 which communicatestherewith and also communicates with fuel passage 30 from, the deliveryvalve 31, which valve is normally retained in closed position by valvespringiSZ. The delivery valve is adapted to receive fuel from cavity 66through distributing port or Vpassage 33 and annulus 29a. Fuel enterssaid cavity 66 from the discharge end of shuttle piston 35 through ports65, one of which ports is provided for each two engine cylinders.

The hydraulic head 11 is provided with the cross bore 34 in which ispositioned the shuttle piston 3S. Bore 34 is adapted to communicatewithvrotor cavity 68 through ports A36 and 36a, which connect with saidbore`34 adjacent the opposite ends thereof. y

' Shuttle'piston i35`has the inclined orhelical end 37 adjacent'meteringor spill port 67. Shuttle piston 35 is adapted to be rotated about itsairisto adjust the position of helicalsurface 37,A relative'toV port67,'A by an Veccentric pin 40 on shaft 41 vwhereby said shuttle piston35 may be adjusted to `control theV spilling Vof lfuel'throughport 67 tocontrol thefuel quantity. This controls one end of injection.v Spilli'ngthrough? port 38 limitsthe other end of injection. n v nRotating'shuttle'piston 35 changes theV fuel quantity by changing theeffective stroke-ofthe shuttle pistonby varying" the -relationshipbetween metering port 67 and heueal'enn'sl. Y v n The adjustment ofshuttle piston 35 is controlled 'through the gove'rcorlprising themovable governor sleeve 46 on drive shaft 13 and which is adjusted alongythe, rotor or drive shaft by thelcentrifugal weights 47,only'one'ofwhih is shown,-and pivoted lever 48 which has an end49engaging said Asleeve 46 whereupon move- `ment`o`f the sleeve 46 oflever 48 is pivoted about its ixed pivot 50, and the end 51 of lever 48which isconnected to vshaft `41 through lever 52 controls theposition ofthe sleeve 39'.

For automatic control,- the ygovernor spring 53 is adjustedthroughadjustment of lever 54 to which one end of spring 53 is connected-andwhich lever is adapted to Vbe adjusted by movement of an operatingleverexternally of casing or housing 10 whereupon shaft 56 and lever `54 arepivoted to adjust the tension on spring 53 which has an end operativelyconnected to lever 48 adjacent the end thereof 51 for adjusting thegovernor lever in the usual manner. Y n

vIn the operation ofthe device, fuel enters the housing 10 through inletport 23a into sump 24. During the suction stroke ofthe plungers- 17,ports 25a in the rotor are in communication with fill ports 25, whichcommunicate withsump 24.v The plungers 17 are forced outwardly by theplunger spring 1 8 andfuel is sucked 'into ports 25 and 25a into bore 68and into the'spa'ce between plungersV 17.

On 'first .part of the injection stroke of the 'plunger-s, when thepl-ungers 17 are forced towards each other by the lobes on the cam 18,fuel flows for a short time from the cavity or bore 68 around the.plunger grooves 60 through-lspill port 61'in the roto'r to spill port62 back to the sump 24.

By the time groove 60 is closed fromport 61, the ll ports 25a areclosed'from ports'ZS and `pressure can be developed fin the' pumpingchamber. The 'rotor is providedV with one port 64 for each two enginecylinders and theselp'orts are equally spaced and always incommunication" with-the pumping chamber. Ports 36 and 36a aresolariranged that first one and then the other is successively openeltoonev of the ports 64fduring succeeding'injection strokes. The oppositeends of ports 36 and 36a 3 are connected to bore 34 adjacent theopposite ends thereof respectively.

The rotor is also provided `with one port 65 Ifor each two enginecylinders. The ports 65 are equally spaced and always in communicationwith cavity 66. Ports 69 and 69a are so arranged that first one and thenthe other is successively opened to one of the ports 65 duringsucceeding injection strokes. The opposite ends of ports 69 and 69a areconnected to bore 34 adjacent the opposite ends thereof respectively.The number of ports 65 and 64 would be equal in number with the samespacing, but not necessarily with the same angular relationship. Ports65 open to ann-ulus 66 which connects to port 33, to annulus 29a todelivery valve 31.

On the iirst injection stroke the piston 35 will be in the positionshown in Fig. 2 with ports 36a and 69 closed. Fuel flows through port 64and port 36 into bore 34 applying pressure to the adjacent end of piston35. This pressure causes pis-ton 35 to move .forcing fuel out of bore69a.

From passage 69a fuel passes through port 65 through annulus 66, port 33to annulus 29a to the delivery valve 31 from which the fuel goes throughport 30 to annulus 29 to the distributor slot 28 on the rotor and thenis delivered to one of the outlets 26. Fuel continues to flow in thisdirection until spill port 38 is uncovered by adjacent end'of piston 35.

On the second injection stroke ports 36a and 69 will be open and ports36 and 69a will be closed. Fuel flows passages adapted to connect theopposite ends of said' through port 64 and port 36a into bore 34applying pressure to the adjacent end of piston causing piston'35 to bedisplaced and forcing fuel out of bore 69 into port 65 and thence to thenext outlet 26. Fuel continues to ow in this direction until spill port67 is uncovered by helical edge 37. The high pressure fuel can nowescape from port 67 to sump 24 and piston 35 will not'mo've any fur--ther in this direction because the fuel pressures against the oppositeends of the piston are practically equal until the instant of spill and,thus, spill port 67 limits the distance of travel of the piston.Uncovering of spill port 38 limits the piston travel in the oppositedirection. Varying the angular relationship between helical end 3 andport 67 will vary the fuel quantity spilled thereby varying the distanceof travel of the piston 35 and varying the fuel quantity delivered. Itwill be seen that whateverV distance the piston travels in one directionfor one injection stroke, it must travel backward exactly the sameamount for the next injection stroke, if the sleeve position is notchanged. Therefore, the amount of fuel injected b'y the forward strokeof the shuttle piston is equal to the amount injected by the backwardstroke and changing the sleeve position changes the fuel quantity thesame amount for the both strokes.

With Vthe present arangement, means is provided for hydraulicallybalancing the shuttle piston forces and pro- Viding a control formetering on the shuttle piston. This control requiresronly very lightforces to change its position for easier governor control and fuelmetering.

It will be seen that with the present arrangement i'as shown, thehydraulic balancing of the pressure eliminates the need for positivemechanical stops.

From the foregoing it will be seen that I have provided new and improvedmeans for obtaining all of the objects and advantages of the invention.

I claim:

l. In a distributor type fuel injection pump for internal combustionengines, a housing having a longitudinal bore, a rotor mounted forrotation in said bore, lsaid rotor having pumping and distributingportions, said pumping portion having radial cylinder means and pistonmeans mounted for reciprocation in said radial cylinder means, cam meansoperatively associated with said piston means for effectingreciprocation of said piston means upon rotation of said rotor, saidrotor having an axial bore conn ecting said pumping and distributingportions, the provision of a shuttle piston bore in said housing andadapted shuttle piston bore to said axial bore in said rotor throughperipherally spaced ports in said rotor, a plurality of outlets in saidhousing, a distributing port in said rotor and communicating with saidaxial bore in'said rotor through said shuttle piston bore and adapted tocommunicate with each of said outlets successively upon rotation-of saidrotor whereby upon rotation of said rotor, fuel pumped by said pumpingportion will be delivered through said axial bore to said distributingportion and then through each of said passages alternately to saidshuttle piston bore and through said peripherally spaced ports in saidrotor and eiect movement of said shuttle piston to effect delivery offuel from the opposite end of said shuttle pistonbore through thepassage to said distributing portion whereby it will be delivered to oneof said outlets, an annular sump in said housing, a fuel inletcommunicating ,withsaid sump, and fuel passage means connecting saidAsump with said axial bore in said rotor, and spill port means adaptedto communicate with said radial cylinder means and with said annularsump.

necting said pumping and distributing portions, the provision of ashuttle piston bore in said housing and adapted to communicate with saidaxial bore upon rotation of said rotor, a shuttle piston mounted forreciprocation in said shuttle piston bore, spill passage connecting saidshuttle piston bore adjacent opposite ends of said shuttle piston Ywithan area of lower pressure, said spill passages being controlled by theopposite ends of said shuttle piston, fuel passages adapted to connectthe opposite ends of said shuttle piston bore to said axial bore in saidrotor through `peripherally spaced ports in said rotor, a plurality ofout- .lets in said housing, a distributing port in said rotor andcommunicating with said axial bore in said rotor through said shuttlepiston bore and adapted to communicate with each of said outletssuccessively upon rotation of said rotor whereby upon rotation of saidrotor, fuel pumped by said pumping portion will be delivered throughsaid axial bore to said distributing portion and then through each ofsaid passages alternately to said shuttle piston bore and through saidperipherally spaced ports in said rotor and effect movement of saidshuttle piston to effect delivery of fuel from the opposite end of saidshuttle piston bore through the passage to said distributing portionwhereby it will be delivered to one of said outlets, and means foradjusting said shuttle piston to vary the spilling ythrough one of saidspill passage means to thereby control the fuel quantity delivered.

tion of said rotor, said rotor having an axial bore connec'tingVV saidVpumping and distributing portion, the provision of a shuttle piston borein said housing and adapted to communicate with said axial bore'uponrotation of said rotor, a shuttle piston mounted for reciprocation insaid shuttle piston bore, spill passages connecting said shuttle pistonbore adjacent opposite ends of said shuttle piston with an area of lowerpressure, said spill passages being controlled by the opposite ends ofsaid shuttle piston, fuel passages adapted to connect the opposite endsof said shuttle piston bore to said axial bore in said rotor throughperipherally spaced ports in said rotor, a plurality of outlets in saidhousing, a distributing port in said rotor and communicating with saidaxial bore in said rotor through said shuttle piston bore and adapted tocommunicate with each of said outlets successively upon rotation of saidrotor whereby upon rotation of said rotor, fuel pumped by said pumpingportion will be delivered through said axial bore to said distributingportion and then through each of said passages alternately to saidshuttle piston bore and through said perpherally spaced ports in saidrotor and effect movement of said shuttle piston to effect delivery offuel from the opposite end of said shuttle piston bore through thepassage to said distributing portion whereby it will be delivered to oneof said outlets, said shuttle piston having a metering edge at one endthereof and means for adjusting said shuttle piston to vary the spillingthrough one of said spill passage means to thereby control the fuelquantity.

References Cited in the tile of this patent UNITED STATES PATENTS2,542,389 Broderick i. Feb. 20, 1951 2,641,238 Roosa June 9, 19532,674,236 Humber Apr. 6, 1954 2,683,445 Seaver July 13, 1954

